Correction: A sensitive OFF–ON–OFF fluorescent probe for the cascade sensing of Al3+ and F− ions in aqueous media and living cells

Correction for ‘A sensitive OFF–ON–OFF fluorescent probe for the cascade sensing of Al³⁺ and F⁻ ions in aqueous media and living cells’ by Lingjie Hou et al., RSC Adv., 2020, 10, 21629–21635, DOI: 10.1039/D0RA02848G.

The authors regret that an incorrect version of Fig. 4 was included in the original article. The correct version of Fig. 4 is presented below.Open in a separate windowFig. 4The ESI-MS spectrum of Al³⁺–HNS complex.The Royal Society of Chemistry apologises for these errors and any consequent inconvenience to authors and readers.     

Correction: iTRAQ-based quantitative proteomic analysis for identification of biomarkers associated with emodin against severe acute pancreatitis in rats

Correction for ‘iTRAQ-based quantitative proteomic analysis for identification of biomarkers associated with emodin against severe acute pancreatitis in rats’ by Hong Xiang et al., RSC Adv., 2016, 6, 72447–72457.

The authors regret that Fig. 2–4 were shown incorrectly in the original article. An incorrect section of the SAP group in the MPO-immunohistochemical staining (Fig. 2A) and HE staining (Fig. 3) experiments was used in error. In addition, Fig. 4 has been revised to show the zymogen granule, in order to better represent the ultrastructure of the pancreas. The correct versions of Fig. 2–4 are shown below.Open in a separate windowFig. 2Emodin down-regulated the MPO protein expression in pancreas of SAP rats. (A) Effect of emodin on MPO-immunopositive area (brown) staining of pancreatic tissue in SAP rats by immunohistochemical detection. (B) Effect of emodin on MPO-immunopositive area (red) staining of pancreatic tissue in SAP rats by immunofluorescence detection. Images are presented at 200× magnification. The data are presented as the mean ± SD, n = 6. **P < 0.01 versus SO; ^#P < 0.05 versus SAP, ^##P < 0.01 versus SAP.Open in a separate windowFig. 3Emodin improved pancreatic histopathology of SAP rats. Effect of emodin on H&E staining of pancreatic tissue in SAP rats. Images are presented at 200× magnification. The data are presented as the mean ± SD, n = 6. **P < 0.01 versus SO; ^#P < 0.05 versus SAP, ^##P < 0.01 versus SAP.Open in a separate windowFig. 4Emodin attenuated cellular structure changes in pancreas of SAP rats. Representative images of the cells’ ultrastructure in the SO (A), SAP (B), 60 mg kg⁻¹ emodin (C), 30 mg kg⁻¹ emodin (D) and 15 mg kg⁻¹ emodin (E) groups. Images are presented at 25 000× magnification.The Royal Society of Chemistry apologises for these errors and any consequent inconvenience to authors and readers.     

Correction: Efficient removal of cobalt from aqueous solution using β-cyclodextrin modified graphene oxide

Correction for ‘Efficient removal of cobalt from aqueous solution using β-cyclodextrin modified graphene oxide’ by Wencheng Song et al., RSC Adv., 2013, 3, 9514–9521.

The authors regret that Fig. 1 and ​and33 were incorrect in the original article. The SEM images of both GO and β-CD, and the Raman spectra of both, were confused with other samples. The correct versions of Fig. 1 and ​and33 are presented below.Open in a separate windowFig. 1SEM images of (a) GO and (b) β-CD-GO.Open in a separate windowFig. 2Raman spectra of GO and β-CD-GO.The Royal Society of Chemistry apologises for these errors and any consequent inconvenience to authors and readers.     

Correction: Effect of molybdenum carbide concentration on the Ni/ZrO2 catalysts for steam-CO2 bi-reforming of methane

Correction for ‘Effect of molybdenum carbide concentration on the Ni/ZrO₂ catalysts for steam-CO₂ bi-reforming of methane’ by Weizuo Li et al., RSC Adv., 2015, 5, 100865–100872.

The authors regret that incorrect TEM images were shown in Fig. 7 of the original article. The authors would like to use the following correct TEM images, shown in Fig. 7 below. The authors state that this error has no effect upon the conclusions of the article.Open in a separate windowFig. 7TEM images of coke on the spent Mo₂C–Ni/ZrO₂ (a) and Ni/ZrO₂ (b) catalysts. Inset in (b) is magnified shell-like carbon.The Royal Society of Chemistry apologises for these errors and any consequent inconvenience to authors and readers.     

Correction: Dipyrrolyl-bis-sulfonamide chromophore based probe for anion recognition

Correction for ‘Dipyrrolyl-bis-sulfonamide chromophore based probe for anion recognition’ by Namdev V. Ghule et al., RSC Adv., 2014, 4, 27112–27115, DOI: 10.1039/C4RA04000G.

The authors regret that an incorrect version of Fig. 1 was included in the original article. The correct version of Fig. 1 is presented below.Open in a separate windowFig. 1Color changes of receptor DPBS in chloroform upon addition of 5 equiv. of F⁻, Cl⁻, Br⁻, I⁻, H₂PO₄⁻, HSO₄⁻, ClO₄⁻ and AcO⁻ (tetrabutylammonium salts).The Royal Society of Chemistry apologises for these errors and any consequent inconvenience to authors and readers.     

Correction: Bio-conjugation of graphene quantum dots for targeting imaging

Correction for ‘Bio-conjugation of graphene quantum dots for targeting imaging’ by Fei Jia et al., RSC Adv., 2017, 7, 53532–53536.

The authors regret that the versions of Fig. 2 and ​and44 displayed in the original article were incorrect. The loading dye in Fig. 2c should be the artificial marker for molecular weight analysis. The original Fig. 4 did not support the EGFR binding due to the cell endocytosis, and the result has been revised with an improved data set. The correct versions of Fig. 2 and ​and44 are shown below.Open in a separate windowFig. 2(a) The sucrose DGU gradient used for purifying the conjugates. (b) The desired SA@GQDs positions in the DGU column. (c) PL image of the DGU column after ultracentrifuge. (d) Bolt 4–12% Bis–Tris gel electrophoresis analysis of SA@GQDs, anti-mouse@GQDs and Erbitux@GQDs, respectively. The loading dye with confirmed molecule weight was tested as references. (e) The cell viability of conjugate Erbitux@GQDs (SCC cell).Open in a separate windowFig. 4(a) SCC cell imaging by Erbitux@GQDs which is binding to the EGFR receptor of SCC cell membrane. (b) The bright field, and PL picture at different channels. After merging the PL picture of Dapi and GFP channels, the successful staining of membrane and nucleus was observed. The quantum yield of GQDs is much lower than Dapi, and we have to tune the contrast/brightness to reach the same quality between Dapi and GQDs. The emission of Dapi also has some signal in GQDs channel, and we have re-draw the data to get rid of the Dapi signal.The Royal Society of Chemistry apologises for these errors and any consequent inconvenience to authors and readers.     

Correction: Facile one-pot synthesis of silver nanoparticles encapsulated in natural polymeric urushiol for marine antifouling

Correction for ‘Facile one-pot synthesis of silver nanoparticles encapsulated in natural polymeric urushiol for marine antifouling’ by Lu Zheng et al., RSC Adv., 2020, 10, 13936–13943, DOI: 10.1039/D0RA02205E.

The authors regret that an incorrect version of Fig. 2 was included in the original article. The correct version of Fig. 2 is presented below.Open in a separate windowFig. 2TEM images of PUL/AgNPs (a–d); EDS of AgNPs (e); UV-vis spectra of AgNPs (f); FT-IR spectra of urushiol (U); PUL/AgNPs (g); XRD image of AgNPs (h).The Royal Society of Chemistry apologises for these errors and any consequent inconvenience to authors and readers.     

Correction: A p-type multi-wall carbon nanotube/Te nanorod composite with enhanced thermoelectric performance

Correction for ‘A p-type multi-wall carbon nanotube/Te nanorod composite with enhanced thermoelectric performance’ by Dabin Park et al., RSC Adv., 2018, 8, 8739–8746.

The authors regret that an incorrect version of Fig. 8 was included in the original article. The correct version of Fig. 8 is presented below.Open in a separate windowFig. 1FE-SEM images of MWCNT/Te nanorod composites with various MWCNT contents (a) 1 wt%, (b) 3 wt%, and (c) 5 wt%.The Royal Society of Chemistry apologises for these errors and any consequent inconvenience to authors and readers.     

Correction: A guanidyl-functionalized TiO2 nanoparticle-anchored graphene nanohybrid for enhanced capture of phosphopeptides

Correction for ‘A guanidyl-functionalized TiO₂ nanoparticle-anchored graphene nanohybrid for enhanced capture of phosphopeptides’ by Hailong Liu et al., RSC Adv., 2018, 8, 29476–29481.

The authors regret that there was an error in Fig. 3 of the original article, as the three parts of the figure were labelled incorrectly. The correct version of Fig. 3 is presented below.Open in a separate windowFig. 1MALDI-TOF mass spectra of tryptic digests of β-casein: (a) direct analysis and after enriched by (b) GF-TiO₂–GO and (c) TiO₂ (# dephosphorylated fragment).The Royal Society of Chemistry apologises for these errors and any consequent inconvenience to authors and readers.     

Correction: Solution-processed Cu2XSnS4 (X = Fe,Co, Ni) photo-electrochemical and thin film solar cells on vertically grown ZnO nanorod arrays

Correction for ‘Solution-processed Cu₂XSnS₄ (X = Fe, Co, Ni) photo-electrochemical and thin film solar cells on vertically grown ZnO nanorod arrays’ by Anima Ghosh et al., RSC Adv., 2016, 6, 115204–115212.

The authors regret that there were two errors in the original article. In the “Experimental details” section on page 115205, “1 M sodium sulfide at 70–80 °C for 24 h” should have read “0.5 M sodium sulfide at 70–80 °C for 24 h”. Additionally, Fig. 3 parts (b)–(d) were mistakenly reproduced from the authors’ previous publication (ref. 33 in the original article). The correct Fig. 3 is presented below.Open in a separate windowFig. 3(a and b) FESEM images of ZnO nanorod arrays, ZnS sensitized ZnO nanorods; (c and d) cross-sectional images of ZnO nanorod arrays and ZnS sensitized ZnO nanorods. The inset in panel (a) shows ZnO nanorod arrays and the inset in panel (b) shows a magnified view.The Royal Society of Chemistry apologises for these errors and any consequent inconvenience to authors and readers.     

Correction: Three-dimensional directional nerve guide conduits fabricated by dopamine-functionalized conductive carbon nanofibre-based nanocomposite ink printing

Correction for ’Three-dimensional directional nerve guide conduits fabricated by dopamine-functionalized conductive carbon nanofibre-based nanocomposite ink printing’ by Shadi Houshyar et al., RSC Adv., 2020, 10, 40351–40364, DOI: 10.1039/D0RA06556K.

The authors regret that an incorrect version of Fig. 2 was included in the original article. The correct version of Fig. 2 is presented below.Open in a separate windowFig. 2(a) FTIR spectra of pure PCL and PCL printed with CNF and DA (40 and 100 μg mL⁻¹), where circles emphasize the OH peak (3700 cm⁻¹) of the carboxylated CNF and NH peak (1565 cm⁻¹) of dopamine. (b) Shear stress of the CNF and CNF + DA nanocomposite inks versus shear rate. (c) Viscosity versus shear rate of the prepared nanocomposite inks.The Royal Society of Chemistry apologises for these errors and any consequent inconvenience to authors and readers.     

Correction: A novel biocompatible,simvastatin-loaded,bone-targeting lipid nanocarrier for treating osteoporosis more effectively

Correction for ‘A novel biocompatible, simvastatin-loaded, bone-targeting lipid nanocarrier for treating osteoporosis more effectively’ by Shan Tao et al., RSC Adv., 2020, 10, 20445–20459, DOI: 10.1039/D0RA00685H.

The authors regret that incorrect versions of Fig. 7, ​,99 and ​and1010 were included in the original article. The correct versions of Fig. 7, ​,99 and ​and1010 are presented below.Open in a separate windowFig. 7Histological analysis of organs from all experimental groups. H&E staining of heart, liver, spleen, lung, kidney, indicating the carrier has good biocompatibility. Scale bar = 50 μm.Open in a separate windowFig. 9Alkaline phosphatase (ALP) activity (arrows) and tartrate-resistant acid phosphatase (TRAP) assay results (arrowheads) of bone tissue sections. Scale bar = 50 μm. The ALP activity is much more high in SIM/LNPs and SIM/ASP₆-LNPs groups, while the TRAP activity is the opposite.Open in a separate windowFig. 10Histological assessment of bone formation in all experimental groups. (A) HE staining of femur bone. Scale bar = 50 μm. Histology of bone in the all experimental groups shows all ovariectomized groups had a higher amount of adipose tissue than Sham group. The trabecular bone is much more prominent in SIM/LNPs and SIM/ASP₆-LNPs groups. (B) Immunohistochemical staining for BMP-2 in typical newly-formed bone tissue (red arrows) and immunohistochemical staining for the osteogenic markers osteopontin (OPN, arrows) and osteocalcin (OCN, arrowheads). Scale bar = 50 μm. The BMP-2, OPN, OCN are much more prominent in SIM/LNPs and SIM/ASP₆-LNPs groups.The Royal Society of Chemistry apologises for these errors and any consequent inconvenience to authors and readers.     

Correction: Highly porous core–shell chitosan beads with superb immobilization efficiency for Lactobacillus reuteri 121 inulosucrase and production of inulin-type fructooligosaccharides

Correction for ‘Highly porous core–shell chitosan beads with superb immobilization efficiency for Lactobacillus reuteri 121 inulosucrase and production of inulin-type fructooligosaccharides’ by Thanapon Charoenwongpaiboon et al., RSC Adv., 2018, 8, 17008–17016.

The authors regret that Fig. 9 in the original article was displayed incorrectly. The correct version is shown below.Open in a separate windowFig. 9Batch reusability of INU-CSBs for IFOS synthesis. Reaction condition: 10 U mL⁻¹ of biocatalysts were incubated with 200 g L⁻¹ sucrose in acetate buffer pH 5.5, 40 °C and 2 h per batch.The Royal Society of Chemistry apologises for these errors and any consequent inconvenience to authors and readers.     

Dual stimuli-responsive lanthanide-based phosphors for an advanced full-color anti-counterfeiting system

Dual stimuli-responsive lanthanide (Ln)-based phosphors were prepared for constructing a multi-level full color anti-counterfeiting system. The encrypted information can be visually read out under UV irradiation. Further triggered by water, not only are the fluorescence colors changed, but so are the patterns of the encrypted information. The Ln-based phosphors can be cost-effectively prepared in a simple way, presenting great potential application in constructing an advanced anti-counterfeiting system with a convenient authentication assay.

Dual stimuli-responsive lanthanide-based phosphors were prepared for constructing a multilevel full color anti-counterfeiting system, augmenting the security level for information protection.

Counterfeiting in numerous fields has become a big concern all over the world. Not only can tremendous loss in economy be caused by counterfeited items such as documents, banknotes, and luxury products, but devastating consequences for an individual, for example, injury, disease, or even death, can also be caused by counterfeited machinery parts or pharmaceuticals.^1–3 Therefore, developing anti-counterfeiting techniques such as barcodes, watermarks, and box seals has drawn ever increasing attention.^4–6 However, most of the assays are easily cloned due to their predictable and fixed encoding mechanisms. It is still a great challenge to construct advanced anti-counterfeiting techniques to improve the level of security.In recent decades, fluorescence-based materials including semiconductor nanocrystals, carbon dots, metal nanoclusters, up-conversion nanoparticles, and lanthanide-based (Ln-based) materials have been utilized in extensive anti-counterfeiting fields, where the colorful emissions of the fluorophores are considered as security elements.^7–10 Fluorescent patterns in banknotes and documents such as birth certification and passport are well-known anti-counterfeiting samples. It is noted that most of information is encoded with single-color fluorescence tags which is not safe enough since it can be feasibly replicated.^11–13 To address the challenge, multicolor or dual-mode anti-counterfeiting systems have been developed to augment the security level.^14–19 Though the anti-counterfeiting systems are superior to those encoded with single-color phosphors, the encoded information still can be decrypted under ultraviolet or infrared irradiation. Chemical or physical stimuli-responsive fluorescent materials provide an alternative way for further augmenting the security level.²⁰Among the fluorescent materials, Ln-based materials arouse a growing interest in construction of anti-counterfeiting owing to their attractive functional properties, such as large stokes shift, sharp-emission luminescence, high pure luminescence, and photostability.^21–23 It is noted that most of the reported Ln-based fluorescent materials are easily quenched by water,^24,25 which limits their practical applications. On the other point, however, the fluorescence quenching by water can be used as advantage in anti-counterfeiting system.²⁶ In the present investigation, a novel Ln-based material has been feasibly synthesized according to the coordination between DPA (2,6-pyridinedicarboxylic acid) and Ce³⁺, DPA–Ce, which presents blue emission in ethanol while not in water. By further doping guanosine 5′-monophosphate (GMP), the produced complex of DPA–Ce–GMP exhibits bright blue emission even in water, furthermore, DPA–Eu–GMP with red emission in water, ethanol and solid powder is also successfully prepared by simply mixing the DPA, Eu³⁺, and GMP. To enrich the phosphors for fabrication of anti-counterfeiting tags, solvent-related green-emitting complex of DPA–Tb and the red-emitting complex of DPA–Eu are synthesized according to previous reports with further simplified,²⁷ both of which exhibit fluorescence in solid powder and ethanol while not in water. By taking advantage of different fluorescence responses of the trichromatic phosphors on water, not only fluorescence color but patterns of the anti-counterfeiting tags are changed under assistance of water, augmenting security level for information protection.As is known that DPA can offer oxygen atoms of the carboxyl group and nitrogen atoms of the pyridine ring and is usually used as remarkable “antenna” for coordinating with Ln(iii) to prepare green and red phosphors while seldom for preparing Ln-based blue phosphors.^28–30 Herein, the blue-emitting DPA–Ce is feasibly prepared by first blending DPA and Ce³⁺ in ethanol and then exposing the mixture under UV lamp irradiation (302 nm, 60 W) for 20 min (Fig. 1A). The formation of DPA–Ce is confirmed by its X-ray photoelectron spectroscopy (XPS) (Fig. 1B) that binding energy peaks at 285 eV, 400 eV and 532 eV are attributed to the character of O1s, N1s, and C1s from DPA. The feature binding energy peaks of Ce3d_5/2 at 886 eV and Ce3d_3/2 at 904 eV are correspondingly detected.^31,32 The X-ray diffraction (XRD) patterns of pure DPA show the typical peaks with high intensity, while no strong diffraction peak can be seen from the XRD pattern for the DPA–Ce (Fig. S1^†), indicating that the crystallinity is lost after chemical coordination with Ce³⁺. The results indicate the successful preparation of DPA–Ce. To elucidate the fluorescence emission mechanism of the DPA–Ce, a series of control experiments were implemented. As illustrated in Fig. 1A, DPA exhibits dim fluorescence (a), which has no change after being irradiated by UV light (b). No obvious fluorescence signal is monitored from Ce³⁺ before and after UV irradiation for 20 min (c and d). The mixture of DPA and Ce³⁺ also exhibits weak blue emission before UV induction (e). Interestingly, the blue emission is significantly augmented under continuous UV induction (f) and reaches maximum after being irradiated for 20 min (Fig. S2^†). Following the same procedure, the influence of ligand and lanthanide ions for the preparation of blue phosphor are further explored. Meanwhile, no fluorescence emission is monitored if replacing ligand by acid (BOP) or replacing lanthanide ions by Gd³⁺, Ln³⁺, or Tm³⁺ (Fig. S3^†). The results indicate that the blue emission of DPA–Ce is attributed to the synergistic function of DPA, Ce³⁺, and UV induction. The augmented emission spectrum of DPA–Ce can be split into two Gaussian peaks with maximum intensity at 402 nm (red-dot curve in Fig. 1A) and 442 nm (black-dot curve in Fig. 1A). The energy difference between the two peaks is about 2000 cm⁻¹ and is consist with the characteristic splitting of the two 4f (2f_5/2 and 2f_7/2) ground levels of Ce³⁺ triggered by spin–orbit interaction.^33,34 Electron in the 4f energy level of Ce³⁺ is firstly pumped into the upper 5d energy level, then non-radiatively relaxes to the lowest 5d energy level,³⁵ and finally radiatively relaxes to the 4f energy levels, resulting in ligand-centered blue emission (Fig. 1C).³⁶ The optimized fluorescence emission of DPA–Ce is found at 2 : 1 molar ratio of Ce³⁺-to-DPA (Fig. S4^†). As is well known that red (R), green (G) and blue (B) phosphors are considered as trichromatic substrates to construct full color materials. According to previous reports,²⁷ phosphors of green-emitting DPA–Tb and red-emitting DPA–Eu are feasibly prepared within 5 min via blending DPA with Tb³⁺ (Fig. 1E(a)) or Eu³⁺ (Fig. 1F(a)) in ethanol, respectively. The DPA–Ce, DPA–Tb and DPA–Eu present similar solvent-related fluorescence property that they exhibit fluorescence in ethanol (curve a in Fig. 1D–F, respectively) and phosphate buffer (PB) (curve b in Fig. 1D–F, respectively) while lose their fluorescence in water (curve c in Fig. 1D–F, respectively).Open in a separate windowFig. 1(A) The excitation and emission spectra of DPA before (a) and after (b) UV induction for 20 min, Ce³⁺ before (c) and after (d) UV induction for 20 min, and DPA–Ce before (e) and after (f) UV induction for 20 min. The Gaussian fitting for the emission of DPA–Ce (red and black-dot curves). (B) X-ray photoelectron spectrum of the DPA–Ce. (C) Diagram of ligand-centred emission mechanism of DPA–Ce. The emission spectra and images of DPA–Ce (D), DPA–Tb (E), and DPA–Eu (F) in ethanol (a), PB buffer solution (b) and water (c).Inspired by previous reports that guanosine 5′-monophosphate disodium (GMP) acts as template for preparation of lanthanide-based fluorescence material.³⁷ Here, GMP is used to co-dope with DPA–Ce, DPA–Eu, and DPA–Tb, respectively. It is found that the produced DPA–Tb–GMP loses fluorescence in both ethanol and water (data not shown here), while the produced DPA–Ce–GMP and DPA–Eu–GMP respectively exhibits blue and red emission in both ethanol and water (Fig. 2A and B), which makes it possible for construction of advanced anti-counterfeiting. XPS experiments for element analysis were implemented to validate the successful preparation of DPA–Ce–GMP (Fig. S5A^†) and DPA–Eu–GMP (Fig. S5B^†). Transmission electron microscopy (TEM) images of DPA–Ce–GMP (Fig. S6A^†) and DPA–Eu–GMP (Fig. S6B^†) reveal similar 3D network structure which are attributed to the hydrogen bonding and coordinating interaction among DPA, Ln ions, and GMP. The stability of the as-prepared Ln-based phosphors was further explored since stability is a critic factor for phosphors in practical applications. Here, the results represented with DPA–Eu–GMP, DPA–Tb and DPA–Ce–GMP as R-G-B samples (Fig. 2C). The Ln-based R-G-B phosphors can endure continuous high-power UV irradiation (60 W, 2 h). No obvious fluorescence decay is monitored, indicating the outstanding anti-photobleaching property. After being stored in dark for six months, neglectable fluorescence attenuation is detected from the phosphors (Fig. 2D), revealing the excellent ultralong stability. The thermal stability of the phosphors is further investigated by monitoring their fluorescence responses against temperature. The fluorescence remains slight change even the temperature goes up to 150 °C (Fig. 2E), presenting much better temperature quenching resistance than commercial phosphor YAG: Ce³⁺ in consideration of 60% decrease of emission intensity (from 25 to 150 °C).³⁸Open in a separate windowFig. 2Emission spectra and fluorescent images of DPA–Ce–GMP (A) and DPA–Eu–GMP (B) in ethanol (a) and water (b). The photo-stability against UV irradiation (60 W, 2 h) (D), the stability up to 180 days (E), and the thermal stability up to 150 °C (F) of the Ln-based phosphors by monitoring the fluorescence intensity of DPA–Eu–GMP at 615 nm, DPA–Tb at 545 nm and DPA–Ce–GMP at 402 nm.Once the Ln-based R-G-B phosphors are successfully prepared, full color can be achieved via balancing the relative contents of them. With DPA–Eu–GMP, DPA–Tb, and DPA–Ce–GMP as the raw R-G-B phosphors, the prepared materials display colors covering the whole visible range, which can be conveniently distinguished with naked eyes under UV light irradiation (Fig. 3A). According to the fluorescence spectra (Fig. 3B), the corresponding Commission Internationale de L′ Eclairage (CIE) chromaticity diagrams from 1 to 11 are listed in Fig. 3C. The CIE chromaticity coordinates of DPA–Ce–GMP with blue emission are calculated as (0.13, 0.08) and almost the same as those (0.14, 0.08) for the saturated blue phosphor. The as-prepared DPA–Tb with green emission reports CIE coordinates of (0.21, 0.74) closing to those for the saturated green (0.21, 0.71) phosphor. The CIE coordinates are found at (0.65, 0.31) for DPA–Eu–GMP with red emission, which are close to those for the saturated red (0.66, 0.33) phosphors.³⁹ The fluorescence response is fluently changed from blue to green with increasing relative content of DPA–Tb in its mixture with DPA–Ce–GMP. The increasing of DPA–Eu–GMP in its mixture with DPA–Tb modulates the fluorescence from green to yellow and then orange. The mixtures of DPA–Eu–GMP and DPA–Ce–GMP with different ratio shift the fluorescence emission from red to purple. The corresponding CIE chromaticity coordinates of the generated emission colors distribute in three straight lines, forming a triangle over a wide region to cover full colors. Specially, by finely controlling the relative content of Ln-based R-G-B phosphors at (DPA–Eu–GMP)_0.42(DPA–Tb)_0.29(DPA–Ce–GMP)_0.29, white-light emission is achieved with CIE coordinates of (0.31, 0.33) which are quite proximity to the coordinates of pure white light (0.33, 0.33). TEM images of the white phosphor (Fig. 3D₁) reveal similar framework configuration as that of the single portion of phosphors. The elemental mapping diagram (Fig. 3D₅) discovers that the three elements of Ce, Tb, and Eu (from Fig. 3D₂ to Fig. 3D₄, respectively) randomly distribute over the mixture.Open in a separate windowFig. 3Images (A), emission spectra (B), and the CIE chromaticity coordinates (C) of full color materials prepared with the Ln-based phosphors in ethanol under the uniform UV light irradiation (302 nm): (1) DPA–Ce–GMP, (2) (DPA–Tb)_0.25(DPA–Ce–GMP)_0.75, (3) (DPA–Tb)_0.37(DPA–Ce–GMP)_0.63, (4) (DPA–Tb)_0.75(DPA–Ce–GMP)_0.25, (5) DPA–Tb, (6) (DPA–Eu–GMP)_0.60(DPA–Tb)_0.40, (7) (DPA–Eu–GMP)_0.71(DPA–Tb)_0.29, (8) DPA–Eu–GMP, (9) (DPA–Eu–GMP)_0.37(DPA–Ce–GMP)_0.63, (10) (DPA–Eu–GMP)_0.71(DPA–Ce–GMP)_0.29, (11) (DPA–Eu–GMP)_0.42(DPA–Tb)_0.29(DPA–Ce–GMP)_0.29 under the uniform UV light irradiation (302 nm). (D) TEM image of the white phosphor (D₁) and the elemental mapping diagrams of Ce (D₂), Tb (D₃), Eu (D₄) and the merged diagram (D₅) of D₂, D₃ and D₄.The above results strongly prove that the as-prepared phosphors can be excellent R-G-B emission source for construction of full-color anti-counterfeiting tags. Computerized inkjet printing provides a convenient way for pattern construction. Here, the R-G-B inks prepared with DPA–Eu–GMP, DPA–Tb and DPA–Ce–GMP are used to fill a standard R-G-B ink cartridge in a commercial inkjet printer (Deskjet 1111, HP), which can be used to print anti-counterfeiting scheme in large scale and high-throughput inkjet printing. As illustrated in Fig. 4A, the three hollow yellow boxes of the code pattern (4 × 4 boxes) are designed for position recognition of the code, and the other solid colorful boxes are units for information storage, which are invisible under room light (Fig. 4A₁). Under irradiation of UV light (302 nm), the decrypted colorful fluorescent patterns are found to be identical to the designed code patterns (Fig. 4A₂). Meanwhile, Fig. 4B shows that the as-prepared GMP, advanced anti-counterfeiting tags is further constructed. With DPA–Eu–GMP, DPA–Ce–GMP, and DPA–Tb as R-G-B inks, the information with numbers as model is encoded on a piece of paper, which is directly written with pens loaded fluorescent inks. The numbers are invisible under daylight (Fig. 4B) while display colorful “8683” under UV irradiation (Fig. 4B₁). Here, the two numbers of 8 are written with blue DPA–Ce–GMP and green DPA–Tb. By controlling the writing position of green ink of DPA–Tb, the two 8 are respectively changed as “H” and “E” after being triggered by water in that the fluorescence of DPA–Tb can be quenched by water. Similarly, the 6 and 3 made of two colors are changed as 5 and 7 in red, Fig. 4B₂. The decoded information can be changed not only in color but also in configuration that provides an interesting strategy for improving security level. By further blending the as-prepared phosphors with certain ratio, multicolor inks can be prepared to fabricate advanced anti-freighting tags. Written with the prepared inks the numbers can''t be observed under day-light (Fig. 4C). Irradiated by UV light, the coded numbers can be directly read (Fig. 4C₁) that red 6 is originated from DPA–Eu, blue 1 from DPA–Ce–GMP, green 2 from DPA–Tb, red 9 from DPA–Eu–GMP, blue 0 from DPA–Ce, cyan 7 from mixture of DPA–Tb and DPA–Ce–GMP, orange 5 from mixture of DPA–Eu–GMP and DPA–Tb, magenta 3 from mixture of DPA–Eu and DPA–Ce–GMP, yellow 1 from mixture of DPA–Tb and DPA–Eu. Further triggered by water, the numbers of red 6, green 2, blue 0, and yellow 1 disappear since the fluorescence of DPA–Ce, DPA–Eu, and DPA–Tb is quenched by water. Meanwhile, no change is monitored from blue 1 and red 9 since water has no influence on the fluorescence of DPA–Ce–GMP and DPA–Eu–GMP. For the numbers made of mixture of two phosphors, water cause color change of 7 from cyan to blue, 5 from orange to red, and 3 from magenta to blue (Fig. 4C₃). In this way, the covert information is decoded as colorful “612907531” in the first step and then is converted as “19753” in red (9 and 5) and blue (1, 7 and 3), which provides a new way for authentication purposes in high level. Meanwhile, Fig. S7^† shows that the as-prepared phosphors as the RGB fluorescent labeling agents for the visualization of latent fingerprint. Under UV irradiation, the collected finger prints on the glass slide with clear fingerprint lines could be observed after depositing the DPA–Ce–GMP (A₁), DPA–Eu–GMP (A₂), and DPA–Tb (A₃) powder on the glass slide, which consist with the previous reports.^40,41 Therefore, the as-prepared Ln-based phosphors have a widespread potential application in construction of anti-counterfeiting patterns and information encryption.Open in a separate windowFig. 4Images of the coded input pattern (A), the printed pattern on the paper under daylight (B) and UV light (C). Images of written numbers on the paper by using all fluorescent inks under day light (D) and UV light (E). The image of information changing after being triggered by water under UV light (F). Image of the written numbers on the paper under day light (G) and UV light (H). The image of information changing after being triggered by water (I).In summary, three kinds of novel phosphors of DPA–Ce, DPA–Ce–GMP, and DPA–Eu–GMP have been successfully constructed in a quite simple way. By further integrating phosphors of DPA–Eu and DPA–Tb, full color fluorescent materials are prepared to fabricate multicolor anti-counterfeiting system that exhibits advantage over than monocular ones. The security level for information protection is further augmented on the basis of the different fluorescent response of the Ln-based R-G-B phosphors on water. Not only fluorescent colors but also patters of the as-prepared anti-counterfeiting tags are changed under the function of water. Meanwhile, the security patterns can be printed in large scale and high throughput, which makes it very convenience for the preparation of anti-counterfeiting tags. The developed anti-counterfeiting system has advantages of low-cost preparation, simple fabrication procedure, and convenient authentication way. The investigation opens up a new avenue for fabricating advanced anti-counterfeiting system to protect information in high level.